Image display controller and image display system

ABSTRACT

An image display unit operational interface for easily selecting a lot of functions while checking the content of an underlying image is provided. 
     In an image display control device ( 3 ) for displaying on a display unit ( 5 ) a large menu having a plurality of menu items, and an underlying image, to allow performing menu item selection and operation according to instructions by a user, a controller ( 14 ) for, according to the instructions, selecting and controlling one of either of the large menu and a small menu that has as menu items a lone portion of the menu items in the large menu, and a menu image compositor ( 20 ) for, according to control by the controller, simultaneously displaying on the display unit the small menu together with the underlying image are included.

TECHNICAL FIELD

The present invention relates to control devices for image display, andimage display devices using the control device, and particularly to atechnology for making it easy for a user to operate such devices.

BACKGROUND ART

Digital broadcasting services are expected to be major broadcastingservices in the future. In the digital broadcasting services,compared-to-conventional analog broadcasting, services that arepresented to users, such as interactive functions and multichannelbroadcasting, are expected to become dramatically abundant. In addition,television receiving terminals, beginning with their integration withVCR or DVD systems, have increasingly become sophisticated every year.

Meanwhile, in order for a user to fully utilize such abundant servicesor sophisticated functions, TV receiving sets are desired to achieveoperational interfaces by which the user can easily select desiredfunctions.

As a method of a user's selecting desired functions from a lot offunction menus appropriately (by fewer operational steps, and withoutrequiring background information), as described in Japanese PatentLaid-Open No. 270236/2000, a method of selecting desired functions bydisplaying a GUI (graphical user interface) screen on a TV receiving setscreen has been conceived.

However, regarding an image display device, situations in which the userhas to carry out menu selection while checking the condition of theunderlying image often occur. With conventional technologies in suchcases, because the display area for the underlying image is used fordisplaying menus, the user cannot check the condition of the underlyingimage. Accordingly, it has been required to repeat operations in whichthe user selects a menu, checks the condition of the underlying imageafter the menu operation screen is erased, and if it is not a desiredresult, the user displays the menu screen again to select the menu, andthen again checks the underlying screen. The present invention aims toresolve such problems.

DISCLOSURE OF THE INVENTION

An image display control device relevant to the present invention, inwhich a large menu having a plurality of menu items, and an underlyingimage are displayed on a display unit, and menu item selection andoperation are performed according to instructions by a user, includes: acontroller for, according to the instructions, selecting and controllingone of either of the large menu and a small menu that has as menu itemsa lone portion of the menu items in the large menu; and a menu imagecompositor for, according to control by the controller, simultaneouslydisplaying on the display unit the small menu together with theunderlying image.

Thus, according to the image display control device relevant to thepresent invention, there is a benefit in that the menu operation can beperformed by means of the large menu in a conventional manner, andmeanwhile, for a user familiar with the menu structure of the largemenu, instead of the large menu, through menu operations by means of thesmall menu that never occupies most portion of the screen area, the usercan perform menu operations while checking how the underlying imagevaries by a menu operation.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram illustrating a television receivingsystem according to Embodiment 1 of the present invention;

FIG. 2 is a block diagram illustrating the configuration of thetelevision image receiving system according to Embodiment 1 of thepresent invention;

FIG. 3 is a front view illustrating an example of an instruction signaltransmitter according to Embodiment 1 of the invention;

FIG. 4 is a flowchart for an interrupt signal processing in thetelevision receiving system according to Embodiment 1 of the presentinvention;

FIG. 5 is a diagram illustrating memory mapping for an interrupt vectortable according to Embodiment 1 of the invention;

FIG. 6 is a diagram illustrating memory mapping for an event queueaccording to Embodiment 1 of the invention;

FIG. 7 is a flowchart for an event handler according to Embodiment 1 ofthe invention;

FIG. 8 is a flowchart for menu drawing processing according toEmbodiment 1 of the invention;

FIG. 9 is a tree diagram logically expressing a hierarchical structureof data included in a menu template;

FIG. 10 is a front view of a large menu displayed by the televisionreceiving system according to Embodiment 1 of the present invention;

FIG. 11 is a front view of a small menu displayed by the televisionreceiving system according to Embodiment 1 of the present invention;

FIG. 12 is a flowchart for menu item movement processing according toEmbodiment 1 of the invention;

FIG. 13 is another front view of the small menu displayed by thetelevision receiving system according to Embodiment 1 of the presentinvention;

FIG. 14 is a flowchart for menu switching processing according toEmbodiment 1 of the invention;

FIG. 15 is a flowchart for menu display position changing processingaccording to Embodiment 1 of the invention;

FIG. 16 is a block diagram illustrating the configuration of atelevision receiving system according to Embodiment 2 of the presentinvention;

FIG. 17 is a flowchart for menu display position changing processingaccording to Embodiment 2 of the invention;

FIG. 18 is a view illustrating an example of a menu displaying methodaccording to Embodiment 3 of the invention;

FIG. 19 is a view illustrating another example of the menu displayingmethod according to Embodiment 3 of the invention; and

FIG. 20 is a view illustrating another example of the menu displayingmethod according to Embodiment 3 of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

FIG. 1 is a configuration diagram illustrating a television receivingsystem according to Embodiment 1 of the present invention. In thefigure, TV signals, such as VHF and UHF signals, received by a receivingantenna 1 are inputted to an image display control device 3 via acoaxial cable 2. The image display control device 3 is a device forcontrolling TV programs displayed on a display unit 5 based on controlsignals transmitted from an instruction signal transmitter 4 such as aremote control terminal. Moreover, in the example illustrated in FIG. 1,the image display control device 3 is configured in a form of aso-called set-top box, so as to control the display unit 5 from outsidethe display unit 5. However, the image display control device 3 can bebuilt into the display unit 5 so as to be configured as an integratedunit.

FIG. 2 is a block diagram illustrating the configuration of thetelevision receiving system. In the figure, TV signals received by thereceiving antenna 1 are inputted to the image display control device 3via the coaxial cable 2. In the image display control device 3, a tuner11 is an element or a circuit for selecting only the signals of adesired channel from received signals, and for outputting the signals.In addition, when TV signals to be inputted are digital-TV signals, thetuner 11 can include a function of a digital converter for converting TVsignals that are digital signals into analog signals.

A channel selecting circuit 12 is an element or a circuit for outputtingto the tuner 11 a channel selection requesting signal based on controlby a later-described controller 14.

A video processing unit 13 is an element or a circuit for separatingimage signals and audio signals from the channel signals outputted fromthe tuner 11, and for converting the image signals from color TV signalsinto RGB signals.

The controller 14 is a component for controlling, based on variations instates of components of the image display control device 3, operationsof the components, and is composed of a central processing unit (CPU).

An instruction signal receiver 15 is a circuit or an element forreceiving a signal transmitted from the instruction signal transmitter4, and for generating an interrupt signal for the controller 14, totransmit to the controller 14 a user's operational instruction performedusing the instruction signal transmitter 4. The instruction signalreceiver 15 is connected via an interrupt signal line to the controller14. If the signal transmitted from the instruction signal transmitter 4is an infrared signal, the instruction signal receiver 15 is composed ofa light receiving element, and varies its electrical characteristicsaccording to reception of infrared light, to generate a predeterminedinterrupt signal.

A timer 16 is an element or a circuit for generating pulse waves everyconstant time, composed of a crystal oscillator, and is connected to thecontroller 14 via an interrupt signal line. According to the generatedpulse wave, an interrupt signal for the controller 14 is generated.

A ROM 17 is a nonvolatile storage element or circuit for storing datasuch as instruction codes of a microcomputer program executed in thecontroller 14, menu templates defining menu item structures, image datafor displaying menus, and font data used for displaying the menus.Stored data can be retrieved by specifying its address. In addition, itis preferable to configure the ROM 17 with flash memories. It isbecause, even if power-off occurs, the last operational state justbefore the power-off can be stored.

However, it is not required to configure the entire ROM 17 with flashmemories. It is possible that flash memories are used only to store, forexample, operational content, and generally used ultraviolet-erasableEPROMs (erasable programmable read-only memories) are used for otherdata such as program codes and image data; Moreover, it is not mandatoryto use flash memories because the feature of the ROM 17 to store theprevious operation content does not directly relate to features of thepresent invention. In addition, meaning of words such as “large menu”,“small menu”, and “menu cursor” will be described later.

A RAM 18 is a volatile storage element or circuit for storing temporarydata required by the computer program executed in the controller 14.Stored data can be retrieved by specifying its address as in the ROM 17.

A menu displaying circuit 19 is a circuit for generating, according to acontrol signal from the controller 14, RGB signals for menu images incombination with image data and font data for displaying menus, storedin the ROM 17. A menu image compositor 20 is a circuit or an element forrealizing a so-called picture-in-picture function, in which the videoprocessing unit 13 incorporates RGB signals outputted from the menudisplaying circuit 19 into a screen image by RGB signals separated fromthe television signals.

A D-terminal cable 21 is a cable for transmitting image signalsoutputted from the menu image compositor 20 to the display unit 5.

(Configuration of the Instruction Signal Transmitter 4)

Next, the configuration of the instruction signal transmitter 4 will bedescribed. FIG. 3 is a front view of the instruction signal transmitter4. In the figure, a signal irradiating unit 31 is a component forirradiating radio waves or infrared light according to a user'soperation on the instruction signal transmitter 4.

A power-on/off button 32 is a button that is pressed when the imagedisplay control device 3 is remotely powered on or powered off. In acase in which the image display control device 3 is integrated with thedisplay unit 5, instead of the power-on/off of the image display controldevice 3, the display unit 5 can be powered on or off. Buttons 33 arebuttons that are used for inputting numerals or the like, and used forselecting channel numbers or the like. A button 34 is a button that isoperated when a cursor (a particular indicator for enabling a menu itemcurrently selected by the user to be identifiable, hereinafter simplyreferred to as a “menu cursor”) on the menu displayed on the screen ofthe display unit 5 by the image display control device 3 is movedupward. Moreover, the button 35 is a button that is operated to move themenu cursor to the left. Similarly, the button 36 is a button that isoperated to move the menu cursor downward, and the button 37 is a buttonthat is operated to move the menu cursor to the right. In addition, thebuttons 34 through 37 are generically referred to as item moving keys oritem moving buttons.

A button 38 is a button that is operated to select and determine themenu item on which the menu cursor is displayed, or to decide thenumerals inputted by the buttons 33.

A button 39 is a button for controlling display/nondisplay of a menu.More specifically, when a menu is in display, if the user operates thebutton 39, then the menu is hidden; and meanwhile, when the menu is notin display, if the user operates the button 39, then the menu isdisplayed.

A button 40 is a menu switching button, which is operated to select aplurality of menu displaying methods presented by the present invention.

In addition, in the above explanation, “to operate the button” means anoperation such as pressing the button, or more generally, means a user'saction to generate a certain signal by letting a sensor circuit for eachbutton, which are installed in the image display control device 3 andnot illustrated, detect on/off of a switch due to the user's action, ordetect variations in electrical characteristics of a piezoelectricdevice or a non-contact electrostatic device.

Moreover, although the buttons are disposed on the front face of theinstruction signal transmitter 4 in the example, instead of the buttons34 through 37 and the button 38, an operational unit such as a joystickcan be provided.

(Operation of the Television Receiving System)

Next, the operation of the television receiving system will bedescribed. In the television receiving system, the receiving antenna 1firstly receives television broadcasting signals such as VHF signals andUHF signals, and the tuner 11 extracts only the signal of a desiredchannel from the received signals. Then, the video processing unit 13separates an image signal and an audio signal from the channel signal,to output the image signal to the menu image compositor 20, and tooutput the audio signal to a speaker via an audio amplifier that is notillustrated. The menu image compositor 20 composes a single image fromthe image signal outputted by the video processing unit 13 and the menuimage signal outputted by the menu displaying circuit 19, and outputsthe composed image signal to the display unit 5.

Meanwhile, according to the signal from the instruction signaltransmitter 4 operated by the user, the image display control device 3displays a menu on the display unit 5, so that channel selection,adjustment of the image and the sound volume, and other operations canbe performed.

Hereinafter, the above-described processing will be described morespecifically. The processing in the image display control device 3 iscomposed of processing for generating an event based on an interruptsignal generated from the instruction signal receiver 15 or the timer 16to store the event in a queue (a waiting line), and processing fortaking out the event stored in the queue to control each component ofthe image display control device 3 in accordance with the type of theevent. Hereinafter, the former processing is referred to as interrupthandling, and the latter processing is referred to as event handling.

Firstly, the relationship between the interrupt handling and the eventhandling will be described. In a steady state, the controller 14 isexecuting the event handling. When an interrupt signal is externallyinputted to the controller 14, the controller 14 suspends the eventhandling, and executes the interrupt handling. And, when the interrupthandling is completed, the controller 14 resumes the event handling thathas been suspended.

The following is a more detailed explanation of the above-describedprocessing. When an interrupt signal is inputted to the controller 14,the controller 14 transfers the content of an instruction pointer (aregister for storing an address from which an instruction stream istaken out) to a save area (a stack) allocated in the RAM 18, and thentransfers the start address of the instruction code stream for theinterrupt handling to the instruction pointer (the register for storingan address from which an instruction stream is taken out), to start theinterrupt handling.

(Interrupt Handling)

Next, details of the interrupt handling will be described. FIG. 4 is aflowchart of the interrupt handling. Prior to the handling, thecontroller 14 receives an interrupt signal from a component such as theinstruction signal receiver 15 or the timer 16. The interrupt signal isa signal that is generated irregularly from the viewpoint of thecontroller 14, and is generated independently of the currently executingevent handling. When the interrupt signal is received, the controller 14starts executing the instruction code stream for the interrupt handling.Firstly, in step ST101 in the figure, the controller 14 saves to thestack area all the register values except the instruction pointer. Theprocedure is a procedure necessary for resuming the former procedureafter the interrupt handling is completed.

Then, in step ST102, the controller 14 refers to an interrupt vectortable, and adds to the queue an event corresponding to the interruptsignal. The interrupt vector table indicates a storage area in the ROM17, for storing the correspondence between the interrupt and the event,and the start address of the instruction code stream for an eventhandler exclusively for each event. FIG. 5 is a diagram illustratingmemory mapping for the interrupt vector table. In the figure, an areawith numeral 41-1 is an area for storing an interrupt number 1 (aspecific number is given), and an area with numeral 42-1 is an area forstoring an ID number of the event corresponding to the interrupt number1. In addition, an area with numeral 43-1 is an area for storing thestart address of an instruction code stream of the event handercorresponding to the interrupt number 1. Moreover, for the interruptnumber 2, areas with numeral 41-2, numeral 42-2, and numeral 43-2 areallocated, in which an interrupt number 2, an event ID thereof, and thestart address of the event handler are stored. Subsequently, for otherinterrupt numbers, a group of an interrupt number, an event ID, and anevent handler is likewise stored in this order.

Furthermore, an example of the configuration allocating different valuesfor the interrupt number 2 and the event ID has been described here.However, a configuration allocating an identical value for the both canbe used. In addition, if the both have an identical value, it is notrequired to allocate different areas for the interrupt number and theevent ID in the interrupt vector table.

Next, the configuration of the queue will be described. The queue is astorage area in the RAM 18 for storing a plurality of events based onthe FIFO (first-in first-out) rule. Specifically, a management sectionincluding three components—an event counter, the start address of thequeue, and the end address of the queue, and an event storing sectionfor actually storing events are provided. FIG. 6 is a diagramillustrating an example of memory mapping for such a queue. In thefigure, the event counter 44 is an area for storing the number of eventsthat are stored in the queue. Moreover, the start address 45 of thequeue is an area for storing the address of the area for storing theevent at the top of the queue. The end address 46 of the queue is anarea for storing the address of the area for storing the last event inthe queue. Here, the queue stores events based on the FIFO rule, so thatthe event stored in the area of the address preserved in the startaddress 45 of the queue is the oldest event, and is the event to be,processed first. And, the event stored in the area of the addresspreserved in the end address 46 of the queue is the newest event, and isthe event to be processed last.

Also in FIG. 6, the event storing section 47 is an area for storing oneor more events. The portion surrounded by numeral 48 in the figure is adiagram for explaining in more detail the state of the event storingsection 47. Here, the events stored in the event storing section 47 arereferred to as Event 1, Event 2, . . . , and Event n. Event 1 iscomposed of an event content 49 and the next event address 50. The eventcontent 49 is an event ID of the event. And, the next event address 50is an area for storing the address of a storage area in which Event 2 isstored. All events after Event 2 have the similar structures. Morespecifically, the event storing section 47 is a storage area expressedas data with list structures, so that the data is not necessarilysequentially stored in the order of Event 1, Event 2, . . . , and Eventn. And, for the last Event n, an event content 51 and the address 52 ofa free space 53 are stored.

In step ST102, the controller 14 adds the event to the queue. In theprocessing, the area in which the last Event n is stored is obtained bythe end address 46 of the queue being referenced, then the address ofthe free space 53 of the last event n is stored in the end address 46 ofthe queue, and meanwhile a new event ID and the next free space addressare stored in the address of the free space 53.

In step ST103, “1” is added to the number of events stored in the eventcounter 44, and the result is re-stored in the event counter 44.

Next, in step ST104, all the register values saved in step ST101 aretransferred to each of the registers, to restore the register values.Then the instruction pointer value is restored, and the interrupthandling is terminated.

As described above, events are registered in the queue. Meanwhile,during the time other than the time while interrupts are handled, thefollowing event handling is performed.

(Event Handling)

FIG. 7 is a flowchart of the event handling by the controller 14.Firstly, in step ST111, the controller 14 initializes the event counter44 to “0” under the condition in which no events are present immediatelyafter the power-on. Next, in step ST112, the handling awaits for apredetermined time. More specifically, timekeeping is performed usinginterrupt signals due to pulses generated by the timer 16, and executionof an NOP instruction (no operation: an instruction doing nothing) iscontinued until a predetermined time elapses. However, this processingis not mandatory, and is omissible. Next, in step ST113, whether thevalue of the event counter 44 is larger than zero is checked. When thevalue of the event counter 44 is larger than zero, step ST112 recurs.Meanwhile, when the value of the event counter 44 is larger than zero,step ST114 ensues.

In step ST114, the start address 45 of the queue, stored in the queuemanagement section, is referenced, and the top event in the queue isobtained. Next, in step ST115, the interrupt vector table is searched toget the position where the event ID of the event is stored, and thestart address of the event handler corresponding to the event ID isobtained. Then, in step ST116, the event handler is called to handle theevent. Moreover, the content of each event handler will be describedlater. Next, in step ST117, the value of the event counter 44 isdecremented by “1”. Subsequently, in step ST118, the value of the startaddress 45 of the queue is updated to the address of the area in whichthe next event is stored. In step ST119, the storage area that theprevious top event has occupied is released. Then step ST112 recursagain. The flowchart in FIG. 7 illustrates the processing that is beingexecuted until the image display control device 3 is powered off, and isnever terminated.

(Menu Display/Nondisplay Processing)

Next, the operation when the user operates the button 39 of theinstruction signal transmitter 4, more specifically, the menudisplay/nondisplay button will be described. When the user operates thebutton 39, the instruction signal transmitter 4 irradiates from thesignal irradiating unit 31 a signal of infrared light or the like. Thenthe instruction signal receiving unit 15 detects the signal, andtransmits an interrupt signal to the controller 14. The controller 14transforms by means of the interrupt handling the interrupt signal intoan event, which is stored in the queue. Next, in the event handling,because the value of the event counter 44 is not zero (step ST113), theevent caused by the user's operation on the button 39 is taken out ofthe queue (step ST114), and an event handler corresponding to the eventis retrieved from the interrupt vector (step ST115), so that the eventhandler for the menu display/nondisplay switching processing due to theoperation on the button 39 is executed.

FIG. 8 is a flowchart of the event handler for the menudisplay/nondisplay switching processing. In step ST121 in the figure,the controller 14 checks whether the menu is currently displayed. If themenu is in display, step ST122 ensues. In step ST122, the controller 14erases the menu. For this purpose, the controller 14 transmits via aninternal bus a control signal to the menu displaying circuit 19, toinform of discarding the menu. Then, when receiving the control signalinforming of discarding the menu, the menu displaying circuit 19 stopsoutputting the RGB signals that have been outputted to the menu imagecompositor 20 for displaying the menu. When the RGB signal output fromthe menu displaying circuit 19 is stopped, the menu image compositor 20stops the picture-in-picture processing, and composes a screen imageonly from the RGB signals from the video processing unit 13. Theabove-described is the menu erasing processing in step ST122. Afterthat, the menu display/nondisplay event handler is terminated, and stepST117 of the event handling recurs.

Meanwhile, in step ST121, if the controller 14 decides that the menu isnot in display, step ST123 ensues. In step ST123, the controller 14loads a menu template from the ROM 17. Here, the menu template meansdata that defines, for instance, a plurality of menu items and relationsamong the menu items. More specifically, the menu template is a datastructure in which data is hierarchically arranged. FIG. 9 is a treediagram logically expressing a hierarchical structure of data includedin such a menu template. As illustrated in the figure, firstly in themenu template, as the first hierarchy, a data unit referred to as atemplate, such as a template 54, is provided. One or more templates arepresent. Each of the templates is entitled a menu name (for example,“Devices”). The menu name is an identifier or a name, whose duplicationwith others is not allowed. The menu name is referenced by thecontroller 14 during processing of the menu, and is directly displayedon the display unit 5, so that the user recognizes from the name whatthe menu is for. Therefore, it is preferable that a recognizable name isentitled. However, this is not directly related to the features of thepresent invention.

Below the template 54, a hierarchy referred to as a section is provided.One or more sections are present for each template. Each of the sectionsis entitled an identifier or a name, whose duplication is not allowed inthe same template. In the example, a section 55 is entitled “Input”, forinstance, a section 58 is entitled “Output”, and a section 62 isentitled “Rec”. When the menu is displayed, the section name is used asa character string that is also directly displayed to the user, so thatit is preferable that a recognizable name is entitled.

Below the section, a hierarchy referred to as a menu item is provided.For example, below the section 55, a menu item 56 is provided. The menuitem is entitled a character string being the title of the menu item.For example, the item 56 is entitled a name “Ant-A”. This name is acharacter string that is directly displayed in each menu item. Inaddition, information for identifying the image data stored in the ROM17 is provided for each menu. As the information for identifying imagedata, the value of the address in the ROM 17, where each image data isstored, can be used without modification for identifying theinformation, or if the information is managed by a file system, its filename can be attached.

Meanwhile, instead of providing a menu item directly below the section,a hierarchy referred to as a subsection can be provided. For example,below the section 58, subsections 59 and the like are provided. Thesubsections are likewise entitled names that can be uniquely identified.For example, the subsection 59 is entitled a name “Video”, and asubsection 60 is entitled a name “Audio”. These names are directlydisplayed on the display unit 5 as character strings.

Although, in order to logically express the relations among dataconstituting the menu template, the configuration of the menu templatehas been illustrated as a tree diagram in FIG. 9, in practice, the datacan be expressed in binary format, or the data can be expressed by astructured text file such as an HTML document or an XML document. Inshort, the data can be expressed in any format as long as the dataformat can express such a hierarchical structure.

Next, in step ST124, the controller 14 composes from the menu template amenu image, which is outputted to the menu displaying circuit 19. Here,menus include large menus and small menus. A large menu is a type ofmenu display that obscures most of the display in the display unit 5. Alarge display area can be used with the large menu, so that a lot ofmenu items or detailed information can be displayed. A small menu is atype of menu display that obscures only a portion of the display. Only asmall display area can be displayed with the small menu, so that thenumber of menu items to be displayed is limited. However, because thesmall menu occupies only a portion of the display, a screen image (anunderlying image) by RGB signals outputted from the video processingunit 13 can be displayed in the area other than the small menu displayarea. Accordingly, there is a benefit in that the menu operation can becarried out while checking a current status of the display or a channelcontent such as a TV program.

If the menu that has been immediately precedingly displayed is a largemenu, the controller 14 composes a menu image of a large menu as a newlydisplayed menu. Meanwhile, if the menu that has been immediatelyprecedingly displayed is a small menu, a small menu is composed as anewly displayed menu. In addition, the type of the immediatelyprecedingly displayed menu is stored in the ROM 17. Configured as above,even if a power-off occurs between the last displaying of the menu andthe new displaying of the menu, memory of the last menu type ispreserved.

When the menu image generated by the controller 14 as described above isinputted, the menu displaying circuit 19 converts the menu image intoRGB signal, and outputs the signal to the menu image compositor 20. Themenu image compositor 20 composes the RGB signal outputted by the videoprocessing unit 13 and the RGB signal outputted by the menu displayingcircuit 19 by means of picture-in-picture, and outputs the result to thedisplay unit 5. FIG. 10 is an example of a menu image of a large menu,composed as described above. This figure illustrates the example ofconverting the template “Devices” in the menu template in FIG. 9 into amenu image. A rectangle indicated by numeral 62 in FIG. 10 correspondsto the section 55 in the menu template; a rectangle indicated by numeral63 corresponds to the subsection 59 in the menu template; a rectangleindicated by numeral 64 corresponds to the subsection 60; and arectangle indicated by numeral 65 corresponds to the section 61.

FIG. 11 is an example of a small menu that is also composed in stepST124. In the figure, numeral 71 indicates a character string of themenu item title for the small menu. Numeral 72 indicates a graphicalimage corresponding to the menu item. Numeral 73 denotes information onwhere the small menu is positioned in the section or the subsection. Theinformation is displayed as “n/m”, for instance. Here, “m” is the totalnumber of menu items in the section or the subsection. And, given thatthe top menu item in the section or the subsection is “1”, “n” is theorder of the current menu item. Thus, by displaying the information onthe total number of menu items and the position of the current menuitem, in spite of the small menu, the structure of the entire menu canbe indicated to the user, so that, even if the display area is limited,the operability is never lowered.

In addition, arrows indicated by numerals 74 through 77 are signs forindicating that the menu cursor can move in the directions of thearrows. In this example, only the arrow 77 is displayed in light color,and the arrows 74 through 76 are displayed in deep color. Configured asabove, it is indicated to the user in an understandable way that anothermenu item is present in the direction indicated by the arrow displayedin deep color. Moreover, even if, instead of displaying the arrow 77 inlight color, the arrow is not displayed, the same effect can beachieved.

At the last of the processing in step ST124, the type of the displayedmenu (a large menu or a small menu) is stored in the ROM 17. After that,the controller 14 terminates the menu display/nondisplay event handler,and step ST117 of the event handling recurs to continue the next eventhandling.

(Menu Selecting Operation)

Next, the operation when the user operates the buttons 34 through 37, ormore specifically the menu cursor moving buttons, of the instructionsignal transmitter 4 will be described. When the user operates thebuttons 34 through 37, in the same way as for the menudisplay/nondisplay button 39, an interrupt is finally converted into anevent, which is stored in the queue. Next, in the event handling,because the value of the event counter 44 is not zero (step ST113), theevent caused by the user's operation on any of the buttons 34 through 31is taken out of the queue (step ST114), and an event handlercorresponding to the event is retrieved from the interrupt vector (stepST115), so that the event handler for the menu cursor movementprocessing by operating the buttons 34 through 37 is executed.

FIG. 11 is a flowchart of the event handler for the menu cursor movementprocessing. In step ST131 in the figure, the controller 14 determineswhether the menu is currently displayed. If the menu is not in display,the event handler for the menu cursor movement processing is terminated,and step ST117 recurs.

Meanwhile, in step ST131, if it has been decided that the menu is indisplay, step ST132 ensues. Then in step ST132, whether the operated keyis the key 34 is checked. If it is the key 34, then step ST133 ensues,to check whether the current cursor position is on the uppermost menuitem of the section/subsection. If the position is on the uppermost menuitem, step ST134 ensues; and if the position is not on the uppermostmenu item, step ST135 ensues. In step ST134, the controller 14 moves themenu cursor to the lowermost menu item of the section or the subsection.In addition, when the menu cursor is moved, the menu image of the menuitem on which the menu cursor has been present, and the menu image ofthe menu item to which the menu cursor is newly moved are necessary tobe updated. Details of the processing for updating the menu images whenthe menu cursor is moved will be described later.

In step ST135, the menu cursor is moved to the next menu item up of thesection or the subsection. Here, the processing for moving the menucursor will be specifically described. When the displayed menu is alarge menu, “to move the menu cursor” means to return to a normal statethe display of the menu item on which the menu cursor has been present,and to change the display of the new menu item so that the user can seethat the menu cursor is present on the new menu item.

As a displaying method for making it recognizable that the menu cursoris present on the new menu item when the large menu is in display, thereis, for example, a method of performing an exclusive OR operationbetween the bit pattern of RGB values (“0xFF”, “0xFF”, “0xFF”) and themenu image of the new menu item. The benefit of the method is asfollows. Specifically, when the menu cursor is moved to another menuitem, the current menu item needs to be returned to the originaldisplay. In this case, with the method using an exclusive OR, bycalculating once again an exclusive OR between the same bit pattern ofRGB values (“0xFF”, “0xFF”, “0xFF”) and the current-state menu image,the original menu image can be restored. Therefore, the display of thecursor movement can be realized by the extremely simple computation.

Likewise as above, there is another method of determining the RGB valueswhen the menu cursor is present, to be the results of subtracting eachcomponent of the RGB values of the menu image from (“0xFF”, “0xFF”,“0xFF”). For example, when the original RGB values of the menu image are(“0x64”, “0x80”, “0x72”), the results of subtracting each component from(“0xFF”, “0xFF”, “0xFF”) are (“0x9B”, “0x7F”, “0x8C”), which are usedfor the RGB values when the menu cursor is present. When the menu cursoris moved to another item, the RGB values are subtracted again from thevalues (“0xFF”, “0xFF”, “0xFF”), whereby the RGB values are returned tothe original values (“0x64”, “0x80”, “0x72”). The presence of the menucursor can be expressed according to such a method.

In addition, such processing methods are all explained merely asexamples. As another method, by loading and redrawing the original imagedata when the menu cursor is moved, the menu image can be restored. Thepresence of the menu cursor can be expressed according to any othermethods.

Meanwhile, when the small menu is displayed, the display of the menuitem is changed so that the menu item on which the menu cursor ispresent can be displayed within the area of the small menu. Even if thedisplay area of the small menu is small, by reducing each menu itemsize, a plurality of menu items can be sometimes displayed in the smallmenu. In such a case, as the menu cursor moves, a menu item that has notbeen displayed in the small menu is displayed, and the display contentof the small menu area can be scrolled. Moreover, in this case, as forthe menu cursor in the large menu, the menu item on which the menucursor is present can be highlighted or the like, so that the user cansee that the menu cursor is present on that menu item.

After the processing in step ST134 or step ST135, the menu cursormovement event handler is terminated, and step ST117 of the eventhandling recurs.

Meanwhile, in step ST132, if it has been decided that the event is notan event generated as a result of the operation of the key 34, stepST136 ensues. Next, in step ST136, if it has been decided that the eventis an event generated as a result of the operation of the key 36, stepST137 ensues.

In step ST137, whether the current menu cursor position is the lowermostmenu item of the section/subsection is checked, and if it is thelowermost menu item, then step ST138 ensues. In step ST138, because nomenu item is present below the current menu item, the menu cursor movesto the uppermost menu item of the section/subsection.

Meanwhile, in step ST137, if the current menu cursor position is not thelowermost menu item of the section/subsection, step ST139 ensues. Thenin step ST139, the menu cursor moves to the next menu item down.

After the processing in step ST134 or step ST135, the menu cursormovement event handler is terminated, and step ST117 of the eventhandling recurs.

Meanwhile, in step ST136, if it has been decided that the event is notan event generated as a result of the operation of the key 36, stepST140 ensues. Next, in step ST140, if it has been decided that the eventis an event generated as a result of the operation of the key 35, stepST141 ensues.

In step ST141, whether the current menu cursor position is in theleftmost section (the first section in the template) is checked, and ifthe menu cursor is on the menu item in the leftmost section, then stepST142 ensues. In step ST142, because the menu cursor cannot be movedfurther to a left adjacent menu item (a menu item in the previoussection in the menu template), the menu cursor is moved to a menu itemin the rightmost section (the last section in the menu template).

Meanwhile, in step ST141, if the current menu cursor position is not inthe leftmost section, step ST143 ensues. In step ST143, the controller14 moves the menu cursor to the left adjacent menu item.

After the processing in step ST142 or step ST143, the menu cursormovement event handler is terminated, and step ST117 of the eventhandling recurs.

Meanwhile, in step ST140, if it has been decided that the event is notan event generated as a result of the operation of the key 35, stepST144 ensues. Next, in step ST144, if it has been decided that the eventis an event generated as a result of the operation of the key 37, stepST145 ensues.

In step ST145, whether the current menu cursor position is in therightmost section (the last section in the template) is checked, and ifthe menu cursor is on the menu item in the rightmost section, then stepST146 ensues. In step ST146, because the menu cursor cannot be movedfurther to a right adjacent menu item (a menu item in the followingsection in the menu template), the menu cursor is moved to a menu itemin the leftmost section (the first section in the menu template).

Meanwhile, in step ST145, if the current menu cursor position is not theleftmost section, step ST147 ensues. In step ST147, the controller 14moves the menu cursor to the right adjacent menu item.

After the processing in step ST146 or step ST147, the menu cursormovement event handler is terminated, and step ST117 of the eventhandling recurs.

Above description is the explanation of the event handler for the menucursor movement processing. Described as above, in the menu cursormovement, when the user tries to move the menu cursor further upwardeven though the menu cursor is on the uppermost menu item, for example,the menu cursor is moved to the lowermost menu item. Accordingly, allthe menu items can be circularly selected. In order to move the menucursor from the lowermost menu to the uppermost menu, operations such ascontinuing to press a key for a long time are not required, so that theoperability is enhanced.

However, such processing is not mandatory. For example, when the usertries to move the menu cursor further upward even though the menu cursoris on the uppermost menu item, a predetermined warning sound such as abeep sound can be generated to let the user know that the cursor cannotbe moved any further. When the small menu is in display, and only asingle menu item, for example, can be displayed because the area of thesmall menu is small, in order to indicate that the menu cursor is on theuppermost menu item and cannot be moved upward any further, such controlcan be performed, in which the upward arrow 74 in FIG. 11 is displayedin light color, or the upward arrow 74 is not displayed. FIG. 13 is adisplay example of the small menu, illustrating that the menu cursorcannot be moved leftward. In the figure, an arrow 77-2 is displayed inlighter color than the other arrows 74 through 76. By displaying asabove, even though the displaying of the small menu is performed withinthe small area, the user can easily understand the entire menustructure. Accordingly, a useless operation, such as trying to move themenu cursor even though the menu cursor cannot be moved, will not beperformed, so that the operability is enhanced as a whole.

(Switching of Menu Display)

Next, the operation when the user operates the button 40, or morespecifically the menu switching button, of the instruction signaltransmitter 4 will be described. When the user operates the button 40,in the same way as for the other button operations, a type of an eventis finally stored in the queue. Next, in the event handling, because thevalue of the event counter 44 is not zero (step ST113), the event causedby the user's operation on the button 39 is taken out of the queue (stepST114), and an event handler corresponding to the event is retrievedfrom the interrupt vector (step ST115), so that the event handler forthe menu display switching processing by operating the buttons 34through 37 is executed.

FIG. 14 is a flowchart of the event handler for switching the menudisplay. In step ST151 in the figure, the controller 14 checks whetherthe menu switching key has been operated. If it is decided that the menuswitching key has been operated, step ST152 ensues. Otherwise, the eventhandler for switching the menu display is terminated, and step ST117recurs.

In step ST152, the controller 14 checks whether the menu is currentlydisplayed. If it is decided that the menu is in display, step ST153ensues. Otherwise, the event handler for switching the menu display isterminated, and step ST117 recurs.

Next, in step ST153, the controller 14 checks whether the currentlydisplayed menu is the large menu. If the menu is the large menu, stepST154 ensues; and otherwise, step ST155 ensues.

In step ST154, the currently displayed large menu is erased, but thesmall menu is displayed instead. Meanwhile in step ST155, the currentlydisplayed small menu is erased, and instead, the large menu isdisplayed. The display processing for the large menu or the small menu,and the menu erasing processing have been mentioned in detail in theexplanation of “Menu display/nondisplay processing”, the explanationwill be omitted here. In addition, the information on whether thecurrent menu is a large menu or a small menu is stored in the ROM 17,and is used when the menu is redisplayed.

At the end, the event handler for switching the menu display isterminated, and step ST117 recurs.

(Timer Event Handling)

Next, the event handler for timer events will be described. Generally, acrystal oscillator constituting a timer can generate pulses everyseveral microseconds. However, if all the pulses are taken to beconverted into interrupt signals, processing load of the controller 14increases for performing only the timer interrupt handling. Therefore, afilter is generally used to adjust the signals so as to generateinterrupts at several millisecond to several second intervals. Thefilter is most simply realized so that the number of pulse occurrencesis counted by configuring a counter with an electrical circuit, and whenthe number reaches a predetermined value, only a single interrupt signalis generated. However, other methods can be adopted.

Moreover, because a timer is usually used for a variety of purposes,events with various intervals may be stored in the queue. However, as amethod of processing timer events related to menus, the processing forperiodically changing menu display position will be described here.

When the large menu is in display, most of the screen is occupied by thelarge menu, so that there is little room for periodically updating themenu display position. In the meanwhile, when the small menu is indisplay, an occupied area by the small menu is small, so that thedisplay position may be periodically updated.

Even though the occupied area by the small menu is small, underlyingimages might include an image that displays important information at thedisplay position of the small menu. For example, viewers of a morningnews program often watch the program while caring the current timedisplayed on the screen. In such a case, even though the area occupiedby the small menu is small, if the small menu is displayed in theimportant display position of the current time, the time cannot bechecked. Score display and the like in live sport telecast are the same.

However, if the display position of the small menu is periodicallychanged, even though the small menu is displayed temporarily in theposition where the important information in the underlying image isdisplayed, the small menu is not always displayed in the position, sothat functions of the small menu and the information presented by theunderlying image can be utilized at the same time.

After the timer 16 transmits an interrupt signal to the controller 14, atimer event is stored in the queue as an event in the same manner as theevent due to the button operation, and the event counter 44 is updated.Next, in the event handling, because the value of the event counter 44is not zero (step ST113), the timer event is taken out of the queue(step ST114), and an event handler corresponding to the event isretrieved from the interrupt vector (step ST115), so that the eventhandler for timer events is executed.

FIG. 15 is a flowchart of the event handler for the timer eventhandling. In step ST161 in the figure, the controller 14 checks whetherthe event is a timer event. If it is a timer event, step ST162 ensues.Otherwise, the event handler for timer events is terminated, and stepST117 recurs.

Next, in step ST162, the controller 14 checks whether the menu is indisplay. If the menu is in display, step ST163 ensues. Otherwise, theevent handler for timer events is terminated, and step ST117 recurs.

In step ST163, the controller 14 checks whether the currently displayedmenu is a small menu. If the small menu is in display, step ST164ensues. Otherwise, the event handler for timer events is terminated, andstep ST117 recurs.

In step ST164, the controller 14 generates random numbers, and a newdisplay position of the small menu is determined. Then the current smallmenu is erased, and the small menu is displayed in the new displayposition. At the end, the event handler for timer events is terminated,and step ST117 recurs.

Obviously from the above description, the television receiving system inEmbodiment 1 of the present invention is configured so that the menu canbe switched between the large menu and the small menu, whereby a userunaccustomed to menu operations can understand with the large menu theentire options of functions, and a user accustomed to menu operationscan perform the menu operation with the small menu while checking thestatus of the underlying image. In short, regardless of the operationproficiency of the user, a lot of functions that the television systemprovides can be easily utilized.

In addition, in a case in which the display position of the small menuis periodically changed based on timer events, when the display positionis determined by generating random numbers, the display position of thesmall menu can be determined excluding an area close to the middle ofthe screen image. Information that viewers pay attention to is oftendisplayed in the central portion of the screen image. By controlling thesystem so that the small menu is not displayed in the central portion ofthe screen image, the menu operability can be enhanced while a viewercan see the content of a TV program.

Moreover, although in the example, the system is configured so thatinfrared signals or wireless signals are transmitted between theinstruction signal transmitter 4 and the instruction signal receiver 15,the system may be configured so that the both are connected via a signalcable, and that electrical signals are directly transmitted.

Furthermore, it is not necessary for the instruction signal transmitter4 and the instruction signal receiver 15 to be located in physicallyseparated positions. For example, the system may be configured so thatthe image display control device 3 and the display unit 5 are integratedtogether, and that operational buttons equivalent to the instructionsignal transmitter 4 are provided on the chassis.

Moreover, although in the example, the configurations and operations ofthe present invention have been described taking a TV broadcastingreceiving apparatus as an example of the television receiving system,the scope of application of the present invention is not limited totelevision receiving systems, but the invention can be widely applied todevices or systems that display images.

Furthermore, the images does not need to be moving pictures, but can bestill images such as map images displayed in a car navigation system.

Embodiment 2

In Embodiment 1, an example has been described, in which random numbersare generated based on the timer events, and the display position of thesmall menu is changed. In addition to that, the system can be configuredso that the display position of the small menu is determined based onthe displayed content of the underlying image. A television receivingsystem according to Embodiment 2 of the present invention has such afeature.

FIG. 16 is a block diagram illustrating the configuration of thetelevision receiving system according to Embodiment 2 of the presentinvention. In the figure, a video processing unit 13-2 is a componentcorresponding to the video processing unit 13 in FIG. 2, and isconfigured so that, in addition to processing for separating fromchannel signals into image signals and audio signals, image processingis performed to calculate light/shadow distribution in pixels for eachframe and difference signals between frames, and, if a predeterminedcondition is satisfied, then an interrupt signal is generated. Becauseother components having the same numerals as in FIG. 2 are similar tothose in Embodiment 1, the description therefor will be omitted.

Next, the operation of the television receiving system will bedescribed. The television receiving system receives, as the televisionreceiving system according to Embodiment 1, television broadcastingsignals received by the receiving antenna 1, and outputs the imagesignals to the display unit 5 via the tuner 11, the video processingunit 13, and the menu image compositor 20. And, according to the signalfrom the instruction signal transmitter 4 operated by the user, the menuis displayed on the display unit 5, so that various operations can beperformed.

The video processing unit 13 performs the processing for separating fromchannel signals into image signals and audio signals. In addition, inorder to determine an appropriate area for displaying the small menu,the video processing unit converts the separated analog image signalsinto digital signals, performs image processing on the digital signals,which is, for example, once developed in the display memory, andextracts pixel distributions within a frame and variations betweenframes, to output interrupt signals to the controller 14. For thatpurpose, the video processing unit 13 divides the entire image intosmall areas with the same size, and calculates pixel distributions andvariations between adjacent frames for each of the small areas.

FIG. 17 is a flowchart of the image processing performed by thecontroller 13. In step ST201 in the figure, the video processing unit 13initializes a variable H to be the horizontal number of the small areas,and a variable V to be the vertical number of the small areas. Next, thevideo processing unit 13 initializes a counter variable “I” to be “1” instep ST202, and initializes a counter variable “J” to be “1” in stepST203. The counter variable “I” is a counter variable for sequentiallyprocessing each small area in a horizontal direction, and the countervariable “J” is a counter variable for sequentially processing eachsmall area in a vertical direction. In addition, in the followingexplanations, a certain small area is expressed as a small area (I, J).

Next, in step ST204, the video processing unit 13 divides by the numberof pixels the total sum of the pixel values for the pixels in a smallarea (I, J) to calculate the mean pixel value for the small area (I, J).Given that the pixel values for the television receiving system areexpressed in 256 tones, when the pixel value is “255”, the luminancethereof is highest, and the pixel value is “0”, the luminance is lowest.In the RGB expression, because pixel values are present independentlyfor each plane—R (red), G (green), and B (blue), the mean pixel valuecan be independently calculated for each plane, or the mean pixel valuesfor each plane can be further averaged out.

Moreover, instead of evenly weighting all the pixel values in the smallareas, the mean value can be calculated only from the pixels having apixel value of a predetermined value or larger. For example, when thecurrent time is displayed, the characters expressing the time are inhigh luminance, and have large pixel values. Therefore, by selectingonly pixels having a pixel value of a predetermined value or larger, andcalculating the mean value from the pixel values of the selected pixels,the small areas in which the characters are displayed and the rest ofsmall areas can be discriminated.

Next, in step ST205, the video processing unit 13 calculates differencesignals between the previous frame and the current frame for the smallarea (I, J). The difference signal is a variation in value betweenframes for a certain pixel. In the small area in which a lot of pixelshaving a large difference signal are distributed, it can be said thatthe movement as a moving image is large. Here, the difference signal foreach pixel is calculated, and the number of pixels whose absolute valueof the difference signal exceeds a threshold is calculated. In addition,also in this case, a method can be adopted, in which the differencesignal is independently calculated for each plane of RGB, and when avariation of a predetermined value or larger is present in any of theplanes, those pixels are counted. Moreover, the pixels can be countedbased on variation in the total sum of RGB values.

Next, the video processing unit 13 increments the counter variable “J”by “1” in step ST206, and whether “J” has exceeded “V” is judged in stepST207. If “J” has not exceeded “V”, small areas to be processed are leftin a vertical direction, so that step ST204 recurs to perform processingfor the next small area. Meanwhile, if “J” has exceeded “V”, step ST208ensues.

In step ST208, the counter variable “I” is incremented by “1”. Then, instep ST209, whether the counter variable “I” has exceeded “H” is judged.If “I” has not exceeded “H”, small areas to be processed are left in ahorizontal direction, so that step ST203 ensues to perform processingfor the horizontally next small area. Meanwhile, if “I” has exceeded“H”, step ST210 ensues.

Next, in step ST210, from the difference signal distribution for eachsmall area and from the mean pixel value, an appropriate area fordisplaying the small menu is determined. For this purpose, the followingcriteria, for example, are established, to check whether each small areasatisfies the criteria.

(a) The mean pixel value is not larger than a predetermined value, or issmaller than a predetermined value.

(b) The distribution frequency of the difference signals that are notsmaller than the threshold is not larger than a predetermined value, oris smaller than a predetermined value.

Then, candidates for the small menu display area are narrowed downaccording to the following criteria (1) and (2).

(1) If there is a small area that satisfies both (a) and (b), the smallarea is determined to be a candidate for the small menu display area.

(2) If there is no small area that satisfies both (a) and (b), a smallarea that satisfies either (a) or (b) is determined to be a candidatefor the small menu display area.

In addition, in the example, the priority of the criterion (2) is lessthan that of the criterion (1) (only when there is no small area thatmeets the criterion (1), the criterion (2) applies). However, this isnot mandatory, so that a candidate for the small area can be selectedonly by the criterion (2). Moreover, if no small area that, meets thecriteria is obtained as a result of the selection according to thecriteria (1) and (2), the predetermined values in (a) and (b) can bevaried step by step to select candidates for the small area.

Furthermore, if a plurality of such candidates for the small menudisplay area are present, the display area that is closest to thecurrent small menu display area can be selected. The reason is that,when the small menu is in display, if the display position is largelyvaried, the user's eyes become unable to follow the small menu position.In order to avoid such a situation, it is preferable to move the smallmenu to the position as close as possible. However, this is notmandatory.

Establishing the criterion (a) makes it less likely that the small menuis displayed in the small area that includes a lot of bright pixels.Regarding the screen image, information that a viewer pays attention to,such as the face of a performer in a TV program, is often displayedbrighter than the other areas. The criterion (a) makes it possible thatthe small menu is displayed and operated without interfering with theimage that the viewer desires to see.

In addition, establishing the criterion (b) makes it less likely thatthe small menu is displayed in the small area in which pixel valueslargely varies. More specifically, it is made less likely that the smallmenu hides moving portions within the screen image. Because viewers tendto pay attention to moving portions within the video image, this makesit possible to enhance the operability of the small menu while lettingthe viewers check the video content.

Moreover, although the example in which the difference signal iscalculated only between the previous frame and the current frame hasbeen described here, any determination method can be used as long as thedisplay position of the small menu is determined based on temporalvariations in the underlying image. For example, the determination canbe made so that a small area in which variations are statistically smallis selected based on pixel value variations in larger number of frames.

Embodiment 3

In Embodiment 1 and Embodiment 2, the small menu has been described as amenu that occupies a small area in the screen image. However, the systemcan be configured so that, within the large menu area, the menu item onwhich the menu cursor is present is preserved as a small menu, and therest of the area is halftoned, whereby the underlying image in the areaexcluding the menu item on which the menu cursor is present ispractically recognizable.

Moreover, instead of preserving only the menu item on which the menucursor is present, the section or the subsection that includes the menuitem on which the menu cursor is present can be preserved.

FIG. 18 is a diagram illustrating an example of a state in which, whenthe menu cursor is on the section “Input” in the large menu illustratedin FIG. 10, the rest of the area is halftoned, to make the displayedcontent of the underlying image recognizable. As seen from the figure,by halftoning the area other than the section “Input”, a significantportion of the underlying image can be recognized. In such a case, thearea of the section “Input” corresponds to the small menu area.

Furthermore, FIG. 19 is a diagram illustrating an example of a state inwhich the menu cursor on the “Input” section in FIG. 18 has been movedto the next menu item right in the subsection “Output”. In this case,the section “Input” is halftoned, but the menu item in the subsection“Output” is clearly displayed instead. Moreover, FIG. 20 is a diagramillustrating an example of a state in which the menu cursor has beenmoved further to the next menu item right.

In addition, in order to halftone a portion of the large menu display,in the menu image compositor 20 in the image display control device 3 inEmbodiment 1, one out of every several pixels in the area other than theselected menu item/section/subsection is thinned out, and the pixelvalue of each pixel that has been thinned out is replaced with the pixelvalue of the pixel in the same position, outputted from the imageprocessing unit 13.

Moreover, in the menu image outputted from the menu displaying circuit19, each pixel value in the area other than the selected menu item,section, or subsection is reduced to half, for example, and, to thereduced pixel value, the pixel value of the video image from the imageprocessing unit 13 can be added, or other publicly-known halftoningmethods can be used.

INDUSTRIAL APPLICABILITY

As described above, the image display control device relevant to thepresent invention is useful in enhancing operability of devices such asa video display device.

1. An image display control device for displaying on a display unit a large menu having a plurality of menu items, and an underlying image obtained from a broadcasting signal, to allow performing menu item selection and operation according to instructions by a user, the image display device comprising: a controller that selects and controls, according to instructions received from the user, either the large menu or a small menu having only a portion of the plurality of menu items in the large menu; and a menu image compositor that displays on the display unit, according to control by the controller, the large menu or the small menu together with the underlying image, wherein whether or not the large menu or the small menu is displayed is based a menu switching signal received from the user, wherein the controller controls the menu image compositor so as to change the position of the area in which the small menu is displayed based on the displayed content of the underlying image.
 2. An image display control device according to claim 1, wherein the controller controls the menu image compositor so as to display on the small menu different menu items in the large menu according to the instructions.
 3. An image display control device according to claim 1, wherein the plurality of menu items in the large menu has predetermined display order, and the controller controls the menu image compositor so as to indicate, when one of the plurality of menu items of the large menu not displayed in the small menu is adjacent to a menu item displayed in the small menu, the direction in which the adjacent menu item is present.
 4. An image display control device according to claim 1, wherein the controller controls the menu image compositor so as to display information regarding in what position a menu item display in the small menu is displayed in the large menu.
 5. An image display control device according to claim 1, wherein the controller controls the menu image compositor so as to change the display position of the small menu area to an area excluding the central portion of the underlying image.
 6. An image display control device according to claim 1, wherein the controller controls the menu image compositor so as to change the display position of the small menu area according to light/shadow distribution in the underlying image.
 7. An image display control device according to claim 6, wherein the controller controls the menu image compositor so as to change the display position of the small menu area according to temporal variation in the light/shadow distribution in the underlying image.
 8. An image display control device according to claim 1, wherein, when the small menu is displayed, the menu image compositor halftones an area in which the area including the menu items included in the small menu is excluded from the large menu display area, and in the halftoned area transparently displays, on the display unit, the underlying image.
 9. An image display system comprising: a display unit; and an image display control device for displaying on the display unit a large menu having a plurality of menu items, and an underlying image obtained from a broadcasting signal, to allow performing menu item selection and operation according to instructions by a user; wherein the image display control device comprises: a controller that selects and controls, according to instructions received from the user, display of the large menu and a small menu having only a portion of the plurality of menu items in the large menu; and a menu image compositor that displays on the display unit, according to control by the controller, the large menu or the small menu together with the underlying image, wherein whether or not the large menu or the small menu is displayed is based a menu switching signal received from the user; and wherein the controller controls the menu image compositor so as to change the position of the area in which the small menu is displayed based on the content of the underlying image. 